1. Field of the Invention
The present invention relates to a method and apparatus for crimping a contact onto a stripped end of a wire, and more particularly to a method and apparatus for crimping a contact automatically when the end of the wire has been properly inserted into the contact.
2. Background Information
Electrical systems, such as those used on aircraft, often use a cannon plug to connect a disconnectable system. A male plug of the cannon plug includes a group of male contacts called pins, each connected to the end of a respective wire. The female receptacle of the cannon plug includes a group of female contacts called sockets, which receive the pins, and which are also connected to the end of a respective wire. Crimping systems for crimping the contacts onto their respective wire ends are currently available from a number of manufacturers. The current crimping systems move a contact through a feeding mechanism so that the contact is aligned with a set of crimping jaws of a crimping mechanism so that when the jaws close, the contact is deformed around the end of a wire.
FIGS. 1A and 1B show an example of a current crimping system 500. The system 500 has a vibratory bowl 502 used for directing contacts 504 into a guide block 506, where the contacts 504 are moved up into a crimp gun 508, where they are permanently coupled to the end portion 521 of a wire 523. The vibration of the bowl 502 moves the contacts 504 up and onto a track 510. An air line 512 is located with an outlet at the top of the bowl 502 and blows contacts that are not properly aligned back into the bowl 502. The contacts 504 that are properly aligned transfer onto guide rails 514 where they are moved in line to the guide block 506 to a rear side of an alignment opening 516. A piston 517 lifts the contact 504 through the back side of the alignment opening 516 and into a pair of jaws 519 of the crimp gun 508, as shown in FIG. 1B, when an operator depresses a foot pedal 518, shown in FIG. 1A. The end portion 521 of the wire 523 is placed into a front side of the alignment opening 516 through a guide opening 525, which leads to the crimp gun 508, and into a barrel portion 527 of one of the contacts 504. The operator then releases the pedal 518 to activate the crimp gun 508 which crimps the conductive portion 521 of the wire 523 to the contact 504. The crimped assembly (not shown) is then removed.
Although the crimping system 500 is faster than manually aligning the contact 504 and the wire end within the crimp gun 508, the system has a number of limitations. First, the system can only accommodate one type of contact. If an operator desires to use another type of contact, the entire contents of the bowl 502 and rail 514 must be removed and the new type of contacts loaded. If a separate bowl and rail were installed to deliver another contact, then the gun 508 would have to be repositioned with another alignment hole each time the type of contact was changed. Further, the rails tend to jam and are easily damaged making the machine highly unreliable.
Yet another problem with the current system is the need of the operator to prepare the machine for crimping by depressing a foot pedal and then physically hold a wire in the proper position in a contact while releasing the foot pedal 518 to activate the gun 508. The use of the foot pedal 518 and the delay caused by manual activation of the gun 508 introduce production time inefficiencies and delays and increase the chance that the wire end will be moved out of position before the gun 508 is activated. Accordingly, there is a need for a crimping system that accommodates a plurality of types of contacts without requiring significant reconfiguration of the system to change the type of contact. Further, there is a need for a system that automatically senses that the wire end is properly seated in the contact and commences the crimping operation.